A process for manufacturing an electrode for a lithium ion capacitor such as a lithium ion secondary battery includes a pre-doping process in which an electrode material is doped in advance with a lithium ion. By way of example, when a negative electrode (anode) of a lithium ion secondary battery is manufactured, a carbon material such as activated carbon used as an electrode material is doped with a lithium ion.
Conventionally, in such a lithium ion doping process, a carbon material is immersed in a doping tank filled with an electrolyte containing a lithium ion to be doped with the lithium ion (see, for example, Patent Document 1).
Patent Document 1: Japanese Patent Laid-open Publication No. H09-022690
However, in the conventional lithium ion doping process, it takes a long time, e.g., several days, to uniformly dope the entire carbon material with the lithium ion. Due to a long time for the conventional lithium ion doping process, the production efficiency of a lithium ion capacitor is reduced.